A new study commissioned by an advocacy group has found that of 17 popular perfumes tested at random, all contained ingredients that weren't listed on the label, including substances the group says may cause allergic reactions in some people and other substances the group says pose potential health risks.

"Almost any chemical can be put in any fragrance," said Houlihan, who is vice president for research at the Environmental Working Group, one of the primary partners in the CSC. "It is a self-regulated industry."